Commercial power nearly always pays a monthly charge based on the peak deliverable power.

However, the utility rates are regulated, and the regulators allow the power companies to charge customers more to recoup any capital expenditures. Presumably when demand increases, the utilities increase capex to meet the demand.

The utility rates are regulated by people who, in most states, are in the pocket of the utility companies.

The public utility commissions of the US are remarkably corrupt.